diff --git a/lib/gpt/ad/forward/series.py b/lib/gpt/ad/forward/series.py
index 9d98ec26e..849a8262f 100644
--- a/lib/gpt/ad/forward/series.py
+++ b/lib/gpt/ad/forward/series.py
@@ -33,6 +33,8 @@ def promote(other, landau_O):
 
 class series(base):
     foundation = foundation
+    __array_ufunc__ = None
+    __numpy_ufunc__ = None
 
     def __init__(self, terms, landau_O):
         self.landau_O = landau_O
diff --git a/tests/ad/ad.py b/tests/ad/ad.py
index 591266ae5..3c54e43b1 100755
--- a/tests/ad/ad.py
+++ b/tests/ad/ad.py
@@ -392,3 +392,13 @@ def plaquette(U):
 err2 += abs((ref_b_grad - num_b_grad)[1]) ** 2 + abs((ref_b_grad - num_b_grad)[dbeta]) ** 2
 g.message(f"Simple combined forward/reverse test: {err2}")
 assert err2 < 1e-12
+
+#####################################
+# Test numpy array compatibility
+#####################################
+
+On = fad.landau(alpha**2)
+series = fad.series(3, On)
+arr = np.arange(1, 10, 1)
+
+assert isinstance(((series + arr) - (arr + series)), fad.series)